1. Technical Field
The invention relates to electronic communications networks. More particularly, the invention relates to automatic device segmentation and port-to-segment distribution in an electronic communications network having multisegment devices.
2. Description of the Prior Art
A network segment consists of repeaters, end stations, and network cabling (for example, see standard ISO/IEC 8802-3 for information on Ethernet networks). Such network segment has the capacity to transfer a limited amount of data per second. Data are transferred in the form of packets, which contain the address of the sending station (the source address) and the address of the intended recipient (the destination address).
When more than the maximum media speed of network data transfer capacity is required, multiple segments can be used. These segments can be interconnected through the use of bridges (bridges are defined in standard ISO/IEC 10038). The term switch has recently been applied to bridges. Switches are fast bridges which generally do not use a CPU to process the packets. Bridges contain two or more ports, each of which connects to a different segment. When two stations on different segments communicate with each other, the bridge forwards the packets between the two segments. When the stations are on the same segment, the bridge does not forward the packets to any other segment. The bridge may buffer data received on its ports to allow forwarding of the data later onto a different segment that was busy when the transmission first occurred.
As the number of end-nodes which access the network medium grows, it becomes statistically more likely that the medium is in use when a given end-node wants to transmit, thereby requiring the end node to wait. Thus, schemes which increase the amount of potential accessibility to, and throughput of, the network medium, without changing the type of physical network used (preserving the users' investment) are of great use and interest.
One way of increasing this bandwidth is to segment the shared network medium. This limits the number of users who have direct access (i.e. connections) to any one of these segments (or domains). If it is desired to have end-nodes in a domain communicate with end-nodes in other domains, bridging or switching across the segments may be employed, so that network packets for devices that are not in the immediate domain are forwarded until they reach the domain of the destination end-node.
While segmenting the networkcan improve bandwidth, the choice of where to segment, e.g. which nodes should be assigned to which segment, affects the success of the results. If all of the most active nodes remain on the same segment, access for any one of those active nodes is not much improved by this scheme, while the less active nodes on other segments have greatly increased opportunity for access but far less need of it. In this situation, the increased access is wasted on the wrong end-nodes.
One of the problems associated with a segmentable hub is bridging between the various segments. For example, individual segments may remain unbridged. One of the known ways of bridging segments is to use switch technology to take advantage of the multiple segments.
Network systems are inherently complex. A significant amount of technical education is required to understand, configure, and maintain any particular type of physical network, e.g. 10Base-T, Ethernet, Token Ring, or FDDI Bus networks. As the use of networks becomes widespread, the number of users responsible for such networks grows, while those among them who have sufficient knowledge to accomplish these tasks declines.
Thus, schemes which can configure, maintain, or improve network conditions without requiring much specific knowledge on the part of the user are also of great use and interest. Such ease of use, i.e. user friendly, schemes are often encompassed in software which is either embedded in the network device itself or is external to the network devices. Software that is embedded in the network device is generally are known as an agent. The external software is generally known as network management application software and is typically run by a system administrator on a management workstation.
Further, there is a need for balancing the flow of communications and data between nodes on network segments during initialization to obtain more throughput over the network. It would also be advantageous to provide a scheme that could be used for such desirable features as redundancy (providing an alternate path for communication), security (isolation of specific communications), and troubleshooting of a network (by systematic isolation of portions of the network to locate faulty wiring or end nodes).